The present invention relates generally to heat exchangers and more particularly to a heat exchanger having individually removable heat transfer tubes.
Heat exchangers of this type include a series of heat transfer tubes, held by header plates. A housing is fastened to the header plates so as to define a heat transfer chamber which substantially encompasses the heat transfer tubes. The housing includes inlet and outlet ports. The ends of each tube extend beyond the header plates into inlet and outlet chambers.
In operation, a first fluid is passed through the housing, via the inlet and outlet ports, over the heat transfer tubes. A second fluid is supplied to the inlet chamber, passes through the tubes and is withdrawn from the outlet chamber. Heat transfer may occur in either direction, i.e. from the first fluid to the second fluid or visa versa.
There are two important design considerations with respect to heat exchangers. First, it is desirable that the heat transfer tubes be individually removable so as to allow for ready repair. Second, one wishes to maximize the number of tubes and thereby maximize the heat transfer capacity of the unit.
In the past, these two design considerations competed against one another. Individual tube removability required open spaces within the heat transfer chamber and between tubes to allow for maneuvering. This, in turn, decreased tube density and unit capacity.